Water-conserving toilets are known in the art. One known type of water-conserving toilet is a "dual-flush" toilet, that is, a toilet that provides independently flushable urinal and main bowls for the disposal of liquid and solid wastes, respectively. The flushing apparatus associated with the urinal bowl, which is typically smaller than the main bowl, uses less water than that plumbed to the main bowl, hence saving water as compared to a one-bowl toilet that is flushed with the same volume of water, regardless of whether solid or liquid waste are to be flushed. Known dual-flush toilets, however, tend to be unduly complex, particularly with respect to the apparatus for flushing the urinal bowl.
U.S. Pat. No. 3,906,554, for example, discloses a dual-flush toilet that releases different amounts of flush water depending on whether solids or liquids are being flushed. Separate handles are provided for flushing the urinal and main bowls, each handle activating a different chain mechanism and cylindrical flush mechanism. This toilet is rather complex, appears to use more water than necessary to flush the urinal bowl, and the chain-pull system mechanism allows a user to waste water by simply holding the flush lever down.
Other dual-flush toilets use electric or manual valves connected to the water supply line to flush the urinal bowl. For example, disclosed in U.S. Pat. No. 5,448,784 is an electric solenoid that controls a valve for flushing the urinal bowl with water obtained directly from the water supply line. The performance of this system, and in particular the volume of water dispensed to flush the urinal bow, can vary due to variation in the pressure of the water in the supply line. Water from home well systems is typically supplied at a pressure that can vary during the drawing of the water from the well from between 25 and 60 or 70 psi, while municipal water can be supplied at pressures as high as 100 psi. Furthermore, such a toilet can be unsuitable for locations where electrical power is not provided, such as campsites, cottages, or the like.
As another example, disclosed in U.S. Pat. No. 5,301,374 is a manual valve connected to the water supply line for flushing the urinal bowl. Although this valve does not require electricity, it is subject to the drawbacks noted above regarding the use of water from the water supply line, can require intricate plumbing connections and components, and it, too, can be held open, wasting water.
Accordingly, it is an object of the present invention to address these and other drawbacks of the prior art, and to provide a simpler dual-flush toilet.